os/filestore: fix infinit loops in fiemap()

since fiemap can get extents based on offset --> len
but we should consider last extents is retrieved when len == 0
even though it is not last fiemap extents

Signed-off-by: Ning Yao <yaoning@unitedstack.com>

diff --git a/src/os/filestore/FileStore.cc b/src/os/filestore/FileStore.cc
index b07b3b2f43d2a1fb9fe3f16d382f4c325e695d06..5c408e343a44c2bbab0721fdc56ce4adb4792028 100644 (file)
--- a/src/os/filestore/FileStore.cc
+++ b/src/os/filestore/FileStore.cc
@@ -3249,17 +3249,14 @@ more:
     i++;
     last = extent++;
   }
-  const bool is_last = last->fe_flags & FIEMAP_EXTENT_LAST;
+  uint64_t xoffset = last->fe_logical + last->fe_length - offset;
+  offset = last->fe_logical + last->fe_length;
+  len -= xoffset;
+  const bool is_last = (last->fe_flags & FIEMAP_EXTENT_LAST) || (len == 0);
+  free(fiemap);
   if (!is_last) {
-    uint64_t xoffset = last->fe_logical + last->fe_length - offset;
-    offset = last->fe_logical + last->fe_length;
-    len -= xoffset;
-    free(fiemap); /* fix clang warn: use-after-free */
     goto more;
   }
-  else {
-    free(fiemap);
-  }
 
   return r;
 }

diff --git a/src/test/objectstore/store_test.cc b/src/test/objectstore/store_test.cc
index 2a69c72364cc5b37db4d5d61ba811ba20b5f0a99..d42f71b01917033124f9f36276d171370078201c 100644 (file)
--- a/src/test/objectstore/store_test.cc
+++ b/src/test/objectstore/store_test.cc
@@ -451,6 +451,7 @@ TEST_P(StoreTest, FiemapHoles) {
     ASSERT_EQ(r, 0);
   }
   {
+    //fiemap test from 0 to SKIP_STEP * (MAX_EXTENTS - 1) + 3
     bufferlist bl;
     store->fiemap(cid, oid, 0, SKIP_STEP * (MAX_EXTENTS - 1) + 3, bl);
     map<uint64_t,uint64_t> m, e;
@@ -467,6 +468,26 @@ TEST_P(StoreTest, FiemapHoles) {
     ASSERT_TRUE((m.size() == 1 &&
                 m[0] > SKIP_STEP * (MAX_EXTENTS - 1)) ||
                 (m.size() == MAX_EXTENTS && extents_exist));
+
+    // fiemap test from SKIP_STEP to SKIP_STEP * (MAX_EXTENTS - 2) + 3
+    // reset bufferlist and map
+    bl.clear();
+    m.clear();
+    e.clear();
+    store->fiemap(cid, oid, SKIP_STEP, SKIP_STEP * (MAX_EXTENTS - 2) + 3, bl);
+    p = bl.begin();
+    ::decode(m, p);
+    cout << " got " << m << std::endl;
+    ASSERT_TRUE(!m.empty());
+    ASSERT_GE(m[SKIP_STEP], 3u);
+    extents_exist = true;
+    if (m.size() == (MAX_EXTENTS - 2)) {
+      for (uint64_t i = 1; i < MAX_EXTENTS - 1; i++)
+       extents_exist = extents_exist && m.count(SKIP_STEP*i);
+    }
+    ASSERT_TRUE((m.size() == 1 &&
+                m[SKIP_STEP] > SKIP_STEP * (MAX_EXTENTS - 2)) ||
+                (m.size() == (MAX_EXTENTS - 1) && extents_exist));
   }
   {
     ObjectStore::Transaction t;